A non-uniform memory access (Non-Uniform Memory Access, referred to as NUMA) system may include multiple interconnected nodes, and each node is formed of a node controller (Node Controller, referred to as NC) and multiple central processing units (Central Processing Unit, referred to as CPU). Coherence of data between each cache (Cache) is maintained by using a cache coherence (Cache Coherence, referred to as CC) protocol based on a directory inside a node. Because large storage space is needed to store the directory, not all directory entries corresponding to all addresses can be stored into a cache. In the prior art, the directory entries corresponding to part of the addresses may be stored in the cache. When the foregoing cache is entirely occupied by a directory, and a directory entry which corresponds to an address that currently needs to be accessed is not in the directory, a home agent (Home Agent, referred to as HA) selects a directory entry from the directory; if a share status of a CA to a cache line (Cache Line) corresponding to an address in the directory entry is shared (that is, S) status or Any (that is, A) status, the HA sends a snoop (Snoop) request message to the CA, so as to request the CA to perform an invalidating operation on the cache line corresponding to the address in the directory entry to make the shared status, to the CA, of the cache line corresponding to the address in the directory entry be in an invalid (that is, I) status, and then deletes the directory entry from the directory and adds the directory entry which corresponds to the address that currently needs to be accessed into the directory.
However, before the HA replaces a directory entry in a directory, if the share status of a cache line corresponding to an address in the directory entry to be replaced is the S status or the A status, the HA needs to request a corresponding CA to perform an invalidating operation on the data, thereby resulting in a decrease of replacement efficiency.